With methods developed in our laboratory we have been able to clone and maintain in culture glomerular epithelial cells (GC) and mesangial cells (MS) from either dissociated rat glomeruli or expants of whole glomeruli. In order to define the fundamental pathogenetic mechanisms that lead to diabetic glomerulosclerosis, we propose, in this application, to isolate whole glomeruli and homogeneous cultures of GEC and MS cells from normal and diabetic rat kidneys, to study the relationship of the diabetic state of the animal to their metabolism in vitro, without the additional variables encountered in the in vivo situation. The hypothesis that alterations in glomerular hemodynamics, as is frequently encountered in juvenile and experimental diabetes, leads to glomerulosclerosis forms the basis for the studies proposed here. We plan on determining whether there are any alterations in prostaglandin biosynthesis that may lead to altered glomerular hemodynamics and whether such alterations are related to carbohydrate metabolism. This will be accomplished by culturing and studying normal and diabetic glomeruli and cells in media containing different concentrations of glucose with and without insulin. Insulin binding and cyclic nucleotide responsiveness to exogenous hormones by whole glomeruli and homogeneous cultures of glomerular cells from normal and diabetic rats will also be studied.